Magnetic Abrasive Finishing (MAF) has attracted much attention as an advanced nano-finishing technology for achieving high-quality surfaces. This chapter provides a systematic exposition of MAF principles and methodologies. It offers a comprehensive overview of the principles of the MAF process, design principle of magnetic field generator, force analysismaterial removal models, magnetic abrasive preparation and its performance, and other novel MAF technologies. Additionally, the prospects of MAF are discussed.  This chapter is beneficial to researchers and practitioners in related fields due to the significant knowledge related to MAF.